Gutter broom suspension

ABSTRACT

A STREET SWEEPER ROTARY GUTTER BROOM IS MOUNTED TO A VEHICLE FRAME FOR FORE AND AFT SWINGING MOVEMENTS BY WAY OF A PARALLEL LINKAGEPIVOTED TO THE FRAME, THE COMBINATION OF A SPRING AND HYDRAULICALLY POWERED CYLINDER COATING TO EFFECT LOWERING AND RAISING OF THE BROOM TO AND FROM GROUND CONTACT.

United States Patent [191 Larsen [451 July 30,1974

1 1 GUTTER BROOM SUSPENSION [75 l lnventor: Gregory J. Larsen, Claremont,

Calif. l

[73 Assignee: Wayne Manufacturing Company,

Pomona, Calif.

[22] Filed: Sept. 27, 1971 [21] App]. No.: 183,826

52 us. Cl. .L 15/87 [51] Int. Cl EOlh 1/05 [58] Field of Search 15/82-87, 320

[56] References Cited UNITED STATES PATENTS 2,996,742 8/1961 Aimers et a1. 15/87 3,186,016 6/1965 Gehman et al.'.. 15/87 X 3,292,195 12/1966 Schmidt et a1 15/87 3,316,578 5/1967 Tamny 15/87 3,353,199 11/1967 Palmiter et al. 15/87 FOREIGN PATENTS OR APPLICATIONS 2/1965 Germany 15/87 Primary Examiner-Edward L. Roberts Attorney, Agent, or Firm1-l. Calvin White combination of a spring and hydraulically powered cylinder coacting to effect lowering and raising of the broom to and from ground contact.

13 Claims, 7 Drawing Figures l GUTTER BROOM SUSPENSION BACKGROUND OF THE INVENTION the vehicle frame and powered in any of various manners to swing outwardly to gutter sweeping position from-which the broom is retractable to elevated vehicle traveling position. Various different mechanisms have been employed to so mount and manipulate the broom in its bodily movements, but there still remains need for improvements in such mechanisms that could benefit them both structurally andfunctionally.

SUMMARY OF TI-IE'INVENTION Such improvements are achieved by the invention by a simplified gutter broom mounting and control mechanism characterizedby its greater simplicity and capability for performance in a fail-safe manner.

More particularly the invention is characterized by the employment of a power course including most'advantageously affluid pressure actuated cylinder unit having universal joint terminals for attachment at one .end to the sweeper vehicle frame and at. its opposite tom extension which in turn carries a cantilevered parallel linkage pivoted at its inner end to the shaft extension and at its outer end to the direct broom support which may also mount a rotary drive for the broom. The parallel linkage may serve a number of functions among which are controlledlowering of the broom, adjustable variation of its ground pressure, the broom fore and aft tilt, and by the incorporation of a spring or the equivalent in the linkage, absorbtion of impact pressures transmitted from the broom. The parallel linkage serves as an intermediate mechanism for elevation of the broom under control of the power cylinder and outward swinging of the broom under the influence of the spring 15.

The invention has various additional features and objects all of which will be understood from the following description of the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general showing of a typical street or road FIG. 6 is an enlarged isolated view showing the power cylinder and its terminal connections with the sweeper frame and an actuator associated with the parallel linkage; and,

FIG. 7 is a view taken from line 7-7 of FIG. 4 showing the broom direct mounting and its association with the parallel linkage. I

DESCRIPTION OF THE PREFERRED EMBODIMENTS sweeper and the location of the gutter broom in rela- -swung inwardly and elevated to sweeper traveling position.

FIG. 5 is a plan view of FIG. 4 taken from line 5-5.

FIG. 1 is illustrative of a conventional street sweeper vehicle V carrying at one side a gutter broom 10 mounted and controlled as will hereinafter appear for outward and down swinging movement to gutter contact sweeping position, and for retraction inwardly to elevated vehicle travelingposition.

First in generalized reference to certain major components of the broom support and control mechanisms, displacement of the broom and its supporting assembly is powered by what will be termed the cylinder or cylinder unit 11, with the understanding that the unit contains a piston the rod 11a of which projects from open end-of the cylinder, the piston being displaceable by fluid, preferably hydraulic, pressure communicated to the cylinder through suitable connections, not shown. Referring to FIG. 2, the cylinder unit 11 is connected to lever 12 for actuation of a parallel linkage mechanism, generally indicated at 13, which provides cantilevered support from the broom l0 and its drive motor M which may also be hydraulically powered. The linkages 12 and 13 are carried by a support 14 suitably mounted to the vehicle frame F in a manner permitting actuation of the broom'supporting assembly by the cylinder or coil spring 15' in the manner later explained.

In reference now to details first as particularly shown in FIG. 6, the cylinder 11 has at 16 a universal joint connection with the frame F by way of sleeve bearing. 17 on stub shaft 18 depending from the frame, and pivot 19, the effect of the universal joint being to permit both horizontal oscillation of the cylinder and its down and up swinging movements to and from the FIGS. 2 and 5 positions with the cylinder body held against rotation. At the opposite end of the cylinder, the piston rod 11a has auniversal joint connection at 20 with lever 12 as by capacity for turning of the piston in the cylinder and its pivoted connected at 21 with the upper lever terminal 22 rotatably connected to cylindrical extension 12a of lever 12.

Referring to the mounting 14 as shown in FIG. 2 and 4, tubular bearing 23 journals a shaft 24 carrying at its upper end a plate' 25 connected at one side to the spring 15 as shown in FIGS. 3 and 4, the plate being shaped to provide angular stop surfaces 26 and 27 engageable against the frame F or a fixed stop to limit the oscillations of shaft 24 under the influence of the power unit 11 or spring 15. Below the bearing 23 the shaft has an extension 28 to which lever 12 is pivoted at 29 and which mounts the parallel linkage 13. The latter is shown to include an upper rigid inverted channelshaped link 30 also pivoted at 29 to the carrier 28 and having at its outer end a pivotal connection at 31 with a support generally indicated at 32 for the broom and its motor, as will later be more particularly described.

The parallel linkage 13 includes a bottom link 33 in the form of a rod 34 passing through and adjustable longitudinally within pivot bearing 35 mounted to the carrier extension 28. The opposite end of link 33 is pivotally. connected at 36 to the support 32. Link 33 is given the'capacity for linear resilient variability by passage of the rod 34 through'coil spring 38 shouldered against the rod at 39 so that the spring is adjustably tensionable by nut 40 bearing against the pivot 35. The lower rod serves as a shock absorber against horizontal impact. Adjustment of nut 40 changes the fore and aft tilt angle of the broom. Resulting change in spring tension is immaterial.

Above link 33 and in alignment therewith is an intermediate link generally indicated at 42 pivoted at 43 to the upper link 30 and slideable at its opposite end within pivot bearing 46 mounted to the extension 28. Rod 42a of the intermediate link has a threaded extent passing through coil spring 421 bearing against nut 45 and against the pivot 46, the variability of the spring confinement against nut 45 serving the purpose of weight adjustment and the engageability of nut 461 against the pivot bearing serving to limit the relative positions of the parallel linkage components when the linkage assembly is elevated by the power cylinder.

In particular reference to the direct broom supporting structure as shown in FIG. 7, the broom, its drive motor and tilt adjustment are carried by plate 37 having integral side flanges 37a pivoted at 31 to the link 30, the bottom extent of the plate being shown by the dotted lines in FIG. 7. The broom is directly carried by outer adjustable plate 48 shaped as illustrated to provide a supporting base 49 for the motor M. The two plates 37 and 48 are interconnected by pivot 50 so that the broom and motor are bodily adjustable within the range of the-indicated angle to vary the lateral broom tilt. Such adjustment is effected by means ofjack screw 53 having terminal nuts bearing against the flanges 37a and threaded through a rockable pivot 54 displaceable within slot 55 to accommodate the degree of adjustment.

In considering the operation of the described mechanisms, assume first the broom to be in elevated sweeper traveling position asshown in FIG. 4 with the lower end of lever 12 engaged against the top link bridge piece 301 and stop shoulder engaged against the vehicle frame as shown in FIG. 5. In this condition of the assembly the cylinder is maintained in pressurized condition to hold the broom in its elevated retracted position against any counter-influence of the spring 15. For sweeping and movement of the assembly to the FIG. 3

position, the power cylinder 11 is fluid pressurized to swing lever 12 free from the stop 301 allowing the assembly 13 first to swing outwardly'under the influence of spring within a range limited by the engagement of stop shoulder 27 with the vehicle frame. The broom then drops down by gravity to sweeping position.

As previously explained, the broom ground pressure is subject to variation by adjustment of nut 45 to tension the spring 421 in accordance with the desired ground broom pressure. In the course of the sweeping operation, the broom may encounter obstacles, particularly curbs, resulting in transmission of impact shocks to the parallel linkage. Such shocks are assumed by the bottom link spring 38, the resistance of which may have been predetermined. Inwardly directed shocks are absorbed by spring 15.

At the end of the sweeping operation, the broom is retractable to its FIG. 5 position by energizing cylinder 11 to swing and fulcrum lever 12 about pivot 29 in engagement with the bridge piece 301 with the result that substantially Zero moment about the pivot, thereby causing the broom first to lift vertically. Elevation of the broom results in increasing effective cylindertransmitted turning moment about the pivot, the moment increasing until it is sufficient to overcome the action of spring 15. Therefore, the broom will always lift first and subsequently swing inward to its traveling position where the broom is held by the fluid being locked in the cylinder under suitable remote valve control.

I claim:

1. A street sweeper gutter broom suspension system comprising:

a. a support to be carried by the sweeper frame for pivoting about an upright axis,

b. a broom-carrying assembly mounted to said support and swingable outwardly in one direction about said axis and also downwardly to broom sweeping-position and retractable upwardly and toward said frame to sweeper traveling position,

0. a power cylinder unit and a lever movable to engage a rigid member of said assembly inresponse to operation of said unit to elevate thp assembly from said broom sweeping position and to pivot the assembly in the opposite direction about said axis toward said traveling position, and

d. a spring so associated with said support as to be operable to urge the broom assembly to said broom sweeping position at times when the lever is disengaged from said rigid member.

2. A system according to claim 1 in which said support a comprises a tubular bearing journaling a depending oscillatory carrier connected to said assembly b.

3. A system according to claim 1 in which said assembly comprises a parallel pivoted linkage terminally carrying the broom.

4. A system according to claim 3 in which said support a comprises a tubular bearing journaling a depending oscillatory carrier connected to said assembly b.

5. A system according to claim 3 in which said linkage is adjustable to vary the ground pressure exerted by the broom.

6. A system according to claim 3 in which said linkage includes an axially resilient deformable link.

7. A system according to claim 3 in which said linkage includes an upper rigid link and a lower axially deformable spring link functioning to absorb brush im pacts.

8. A system according to claim 1 in which said power cylinder unit has terminal universal joints one of which is connected to a lever engaging said assembly and operable to elevate thebroom.

9. A system according to claim 3 in which said power cylinder unit has terminal universal joints one of which is connected to a lever engaging said assembly and operable to elevate the broom.

10. A system according to claim 3 in which said linkage also includes means for adjustably varying the broom tilt angle and down pressure.

11. A system according to claim 10 in which said means comprises an axially deformable spring operatively connected to a member of said parallel linkage.

12. A street sweeper gutter broom suspension system comprising:

1 a. a support to be carried by the sweeper frame for pivoting about an upright axis,

b. a broom-carrying assembly mounted to said support and swingable outwardly and downwardly to broom sweeping position and retractable upwardly and toward said frame to sweeper traveling position,

c. a power cylinder unit connected to said assembly and operable to elevate the assembly from said broom sweeping position,

d. a spring so associated with said support as to be operable to swing the broom assembly to said broom sweeping position,

from ground contact. 

